act

[ akt ]

/ ækt /

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noun

anything done, being done, or to be done; deed; performance: a heroic act.

the process of doing: caught in the act.

a formal decision, law, or the like, by a legislature, ruler, court, or other authority; decree or edict; statute; judgment, resolve, or award: an act of Congress.

an instrument or document stating something done or transacted.

one of the main divisions of a play or opera: the second act of Hamlet.

a short performance by one or more entertainers, usually part of a variety show or radio or television program.

the personnel of such a group: The act broke up after 30 years.

false show; pretense; feint: The politician's pious remarks were all an act.

Philosophy. (in scholasticism)

activity in process; operation.
the principle or power of operation.
form as determining essence.
a state of realization, as opposed to potentiality.

verb (used without object)

to do something; exert energy or force; be employed or operative: He acted promptly in the emergency.

to reach, make, or issue a decision on some matter: I am required to act before noon tomorrow.

to operate or function in a particular way; perform specific duties or functions: to act as manager.

to produce an effect; perform a function: The medicine failed to act.

to behave or conduct oneself in a particular fashion: to act well under all conditions.

to pretend; feign: Act interested even if you're bored.

to perform as an actor: He acted in three plays by Molière.

to be capable of being performed: His plays don't act well.

to serve or substitute (usually followed by for): In my absence the assistant manager will act for me.

verb (used with object)

to represent (a fictitious or historical character) with one's person: to act Macbeth.

to feign; counterfeit: to act outraged virtue.

to behave as: He acted the fool.

Obsolete. to actuate.

Verb Phrases

act on / upon

to act in accordance with; follow: He acted on my advice.
to have an effect on; affect: The stirring music acted on the emotions of the audience.

act out,

to demonstrate or illustrate by pantomime or by words and gestures: The party guests acted out stories for one another.
Psychology. to give overt expression to (repressed emotions or impulses) without insightful understanding: The patients acted out early traumas by getting angry with the analyst.

act up,

to fail to function properly; malfunction: The vacuum cleaner is acting up again.
to behave willfully: The children always act up in school the day before a holiday.
to become painful or troublesome, especially after a period of improvement or remission: My arthritis is acting up again this morning.

get / have one's act together Informal. to organize one's time, job, resources, etc., so as to function efficiently: The new administration is still getting its act together.

OTHER WORDS FOR act

1 feat, exploit; achievement; transaction; accomplishment.

4 record.

6 turn, routine.

10-13 perform, function, work. play. 19, 21 play.

See synonyms for act on Thesaurus.com

QUIZ

THINGAMABOB OR THINGUMMY: CAN YOU DISTINGUISH BETWEEN THE US AND UK TERMS IN THIS QUIZ?

Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.

Question 1 of 7

In the UK, COTTON CANDY is more commonly known as…

candystring

candyfloss

candypuff

TAKE THE QUIZ TO FIND OUT

Idioms about act

act funny, to display eccentric or suspicious behavior.

act one's age, to behave in a manner appropriate to one's maturity: We children enjoyed our uncle because he didn't always act his age.

clean up one's act, Informal. to begin adhering to more acceptable practices, rules of behavior, etc.: The factory must clean up its act and treat its employees better.

Origin of act

First recorded in 1350–1400; Middle English act(e) (from Middle French ), from Latin ācta, plural of āctum “something done,” noun use of past participle of agere “to do” (āg- past participle stem + -tum neuter past participle suffix); and directly from Latin āctus “a doing” (āg- + -tus suffix of verbal action)

synonym study for act

1. See action.

OTHER WORDS FROM act

mis·act, verb (used without object)postact, nounpre·act, verb (used with object)un·act·ed, adjective

well-acted, adjective

Other definitions for act (2 of 3)

ACT

Trademark. a standardized college admissions test developed by ACT, Inc., measuring English, mathematics, reading, and science skills: originally an abbreviation of American College Testing/American College Test.Compare SAT.

Association of Classroom Teachers.

Australian Capital Territory.

Other definitions for act (3 of 3)

act.

abbreviation

acting.

active.

actor.

actual.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use act in a sentence

The simple act of wearing a covering over one’s mouth and nose has become particularly divisive as some question the changing recommendations issued by top health organizations.
Inconclusive results, missing data: Experts push back on a study questioning the efficacy of masks|Meryl Kornfield|November 20, 2020|Washington Post
In so doing, he dismisses as “very unlikely” the suggestion that Nero ordered the burning of his capital — an act that would have been both illogical and difficult.
What was Nero really doing while Rome burned?|Diana Preston|November 20, 2020|Washington Post
The records act makes no exception for cases in which searching for a public record “would require the state to work hard,” the analysis found.
Junior Staffer Says Top Alaska Official Told Her to Keep Allegations of Misconduct Secret|by Kyle Hopkins, Anchorage Daily News|November 18, 2020|ProPublica
Proving that something is impossible is a powerful act of mathematics.
Some Math Problems Seem Impossible. That Can Be a Good Thing.|Patrick Honner|November 18, 2020|Quanta Magazine

Outside contributor Daniel Duane traveled to Southern California to talk to Corliss about his latest high-wire act.
How BASE Jumping Saved Jeb Corliss's Life|Outside Editors|November 18, 2020|Outside Online
Servis, a general contractor, was baffled by how introverted Stone acted.
Hunt for Iraq Vet After Killing Spree|M.L. Nestel|December 16, 2014|DAILY BEAST
When they thought about Lewis, what struck the players most was that he never acted like a do-gooder.
A West Point MVP Who Never Played a Down|Nicolaus Mills|December 13, 2014|DAILY BEAST
LAPD police chief Charlie Beck concluded Corrales and Diego had acted reasonably.
Worse Than Eric Garner: Cops Who Got Away With Killing Autistic Men and Little Girls|Emily Shire|December 4, 2014|DAILY BEAST
But Stephen Kotkin's new biography reveals a learned despot who acted cunningly to take advantage of the times.
Kotkin Biography Reveals Stalin's Evil Pragmatism|William O’Connor|November 30, 2014|DAILY BEAST
I dressed as a girl, lived as a girl, acted as a girl, and that was that.
Exclusive: Michael Phelps’s Intersex Self-Proclaimed Girlfriend, Taylor Lianne Chandler, Tells All|Aurora Snow|November 26, 2014|DAILY BEAST
Whereas Lessard had acted the martinet with MacRae, he took another tack and became the very essence of affability toward me.
Raw Gold|Bertrand W. Sinclair
He acted dejected and dispirited, and if he could have talked would have asked the meaning of it all.
The Courier of the Ozarks|Byron A. Dunn
Mr. Wainwright acted as secretary and I kept the minute book and papers relating to the business of the committee.
Fifty Years of Railway Life in England, Scotland and Ireland|Joseph Tatlow
Thereupon the unhappy woman acted; the long suppressed outburst came at last.
Dope|Sax Rohmer
This was a somewhat singular mode of stimulating, but he deemed it the wisest course, and acted on it.
Hunting the Lions|R.M. Ballantyne

British Dictionary definitions for act (1 of 3)

act

/ (ækt) /

noun

something done or performed; a deed

the performance of some physical or mental process; action

(capital when part of a name) the formally codified result of deliberation by a legislative body; a law, edict, decree, statute, etc

(often plural) a formal written record of transactions, proceedings, etc, as of a society, committee, or legislative body

a major division of a dramatic work

a short performance of skill, a comic sketch, dance, etc, esp one that is part of a programme of light entertainment
those giving such a performance

an assumed attitude or pose, esp one intended to impress

philosophy an occurrence effected by the volition of a human agent, usually opposed at least as regards its explanation to one which is causally determinedCompare event (def. 4)

verb

(intr) to do something; carry out an action

(intr) to function in a specified way; operate; reacthis mind acted quickly

to perform (a part or role) in a play, etc

(tr) to present (a play, etc) on stage

(intr; usually foll by for or as) to be a substitute (for); function in place (of)

(intr foll by as) to serve the function or purpose (of)the glass acted as protection

(intr) to conduct oneself or behave (as if one were)she usually acts like a lady

(intr) to behave in an unnatural or affected way

(copula) to pose as; play the part ofto act the fool

(copula) to behave in a manner appropriate to (esp in the phrase act one's age)

(copula) not standard to seem or pretend to beto act tired

clean up one's act to start to behave in a responsible manner

get in on the act informal to become involved in a profitable undertaking or advantageous situation in order to share in the benefits

get one's act together informal to become organized or prepared

Derived forms of act

actable, adjectiveactability, noun

Word Origin for act

C14: from Latin actus a doing, performance, and actum a thing done, from the past participle of agere to do

British Dictionary definitions for act (2 of 3)

ACT¹

abbreviation for

Australian Capital Territory

(formerly in Britain) advance corporation tax

British Dictionary definitions for act (3 of 3)

ACT²

/ (ækt) /

n acronym for

(in New Zealand) Association of Consumers and Taxpayers: a small political party of the right

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with act

act

In addition to the idioms beginning with act

act of faith
act of God
act on
act one's age
act out
act up
act upon

also see:

catch in the act
clean up (one's act)
do a disappearing act
get in the act
get one's act together
hard (tough) act to follow
high-wire act
in the act of
put on an act